The invention relates generally to computed radiography systems and methods and more particularly, to computed radiography systems and methods utilizing a two-dimensional imager.
Computed radiography systems employ imaging techniques that capture radiation as they pass through an object to be imaged using an imaging plate coated with a storage phosphor. The object to be imaged is typically exposed with X-rays, and a latent X-ray image is formed on the imaging plate. The storage phosphor on the imaging plate when stimulated with a low energy scanned light beam (such as a laser beam) releases visible light at locations where X-rays are absorbed. The light is then captured and converted into an electrical signal, which is subsequently converted to data that can be transmitted to remote systems or locations and displayed on laser-printed films or softcopy workstations and stored digitally.
Typically, only a portion of the X-ray energy deposited onto the computed radiography phosphor plate is generally stored. A substantial amount of light due to the impinging X-ray energy is emitted promptly at the time of exposure, which is generally not captured by a detector. Therefore, much of the energy deposited onto the computed radiography plates is lost due to failure to collect prompt emission. Further, in existing computed radiography reading processes used to retrieve the stored emission information, some signal remains in the phosphor plate, which is typically wasted during the erasure cycle. The X-ray energy losses due to prompt and non-retrieved stored emission reduce the detective quantum efficiency and signal to noise ratio for X-ray exposures that would otherwise result in a much higher image scan quality. In medical applications, this energy is imparted to the patient without benefit of enhanced diagnosis. In nondestructive testing applications, this wasted energy results in longer throughput cycles for collecting imagery than otherwise desired.
It would therefore be desirable to develop an improved system and technique that enables a more complete and efficient energy collection from the imaging plate.